1. Field of the Invention
This invention relates to a resin U-channel assembly in a formed protector for a wire harness, which receives a plurality of wires to adjust and maintain the shape of the wire harness.
2. Statement of the Prior Art
A resin U-channel assembly in a formed protector for a wire harness (hereinafter referred to as "a formed protector") has a U-shaped cross section with a uniform thickness, in which side plate portions are integrally and vertically connected to the opposite side ends of a bottom plate. The resin U-channel assembly is mass-produced by pouring a molten resin into a forming metal mold having a cavity with the same shape as the U-channel assembly.
The above U-channel assembly mass-produced by the metal mold is characterized in that a contraction coefficient becomes high due to progressive crystallization as the molten resin is slowly cooled and the contraction coefficient becomes low due to cessation of crystallization as the molten resin is quickly cooled, in accordance with the relationship between a temperature of the molten resin to be poured into the cavity and a temperature of the metal mold. Accordingly, the U-channel assembly with a uniform thickness has a high contraction coefficient, since the corners connecting the bottom plate portion and the side plate portions are slowly cooled. Stress due to the high contraction coefficient causes the side plate portions to be bent inwardly.
Since the U-channel assembly in the formed protector is bent inwardly and thus narrows at the opening, a step of inserting the wires into the assembly becomes difficult and a space for receiving the wires becomes small. Further, a cover is fitted on the formed protector with some play, thereby preventing the cover from being locked.